摘要
Olivine phenocryst compositions and whole-rock chemical compositions are used to identify primitive picrite basalts from the early part of flood basalt successions in the western part of the Emeishan large igneous province （ELIP）, southwestern China. The Fo contents of olivine phenocrysts of komatiites with MgO-21.79 wt% range from 85.2% to 91.4%. The composition of unerupted parental melts is calculated from the compositions of the most Fo-rich olivine phenocrysts. These melts had -22 wt% MgO, and originated in mantle with a potential temperature of -1600℃ and at about 4.2 GPa pressure, supporting the conclusion that the generation of ELIP can be attributed to melting of a plume head beginning at -138 km depth.
作者简介
Zhaochong Zhang, graduated from the Department of Geology, Peking University, received his PhD degree at the Graduate School, Chinese Academy of Geological Sciences （CAGS） in 1995, is a research Professor at the China University of geosciences, Beijing. His interest is mainly on igneous petrology and its related ore deposits. E-mail： zhangzhaochong@sohu.com
